Heavy duty track-laying vehicles generally comprise a twist-resistant or torsionally stiff or rigid chassis on which the running or guide rolls or wheels for the tracks are suspended usually with some type of torsion-bar suspension. Because of the considerable weight of such vehicles, it has been found to be advantageous, especially where continuous belt tracks are used, to replace the solid chassis construction by a chassis frame which, however, generally also is torsionally rigid and stiff. This construction has the drawback that forces transmitted during travel from the drive elements, i.e. the wheels or running rolls, to the chassis frame carry generally significant stresses which limit the operational life of the frame members, i.e. by causing premature metal and joint fatigue.